The present invention relates to a facsimile machine having an internal buffer memory.
An internal buffer memory enables a facsimile machine to receive facsimile transmissions when the facsimile machine has run out of paper, or is for some other reason temporarily incapable of printing; store the received facsimile data; and print the data later, after the print-disabling condition has been corrected. This scheme fails, however, if the buffer memory overflows due to the continued arrival of facsimile transmissions before the disabling condition can be corrected. If the buffer memory overflows, a facsimile transmission may be incompletely received, and a transmission error will be reported at the transmitting facsimile machine, causing irritation to the human users at both ends.
If the receiving facsimile machine is interfaced to a personal computer, an alternative scheme is available: incoming data can be transferred to the personal computer system. A choice between these schemes may be available: the facsimile machine may have both an internal buffer memory and a personal-computer interface. In this case, conventional facsimile machines have been designed to use one scheme or the other, but not both. That is, if a conventional facsimile machine is set to transfer incoming data to the personal computer system, it will not store the data in its internal buffer memory. Conversely, if set to store incoming data in its internal buffer memory, the conventional facsimile machine will not attempt to transfer data to a personal computer.
When such a facsimile machine is set to use its internal buffer memory, the original problem still occurs. If the print-disabling condition continues, the buffer may overflow, causing facsimile data to be lost.
Problems also occur when the facsimile machine is set to transfer incoming data to a personal computer system. One problem is that the personal computer itself may be in a disabled condition, so that all incoming facsimile messages are lost. Another problem is that even if the personal computer system is operating normally, the amount of space available for storing files in the personal computer system is unknown to the facsimile machine. If this space becomes exhausted during the reception of a facsimile transmission, the same problems occur as when the facsimile machine's buffer memory overflows. Finally, even when all received facsimile data are successfully stored in the personal computer system, the human user may remain unaware of this, and in any event will not know what facsimile transmissions have been received and stored, or where these facsimile transmissions originated.
A further problem is that many facsimile machines are not interfaced to a personal computer and hence cannot avail themselves of the second scheme described above.